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Lodgepole Pine Cone Density. By: Corey Slinkard EBIO 4100 Spring Semester 2012. Outline. Hypothesis About the Lodgepole Pine Location Importance Reproduction Cones Methods Results Discussion Citations. Hypothesis.
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Lodgepole Pine Cone Density By: Corey Slinkard EBIO 4100 Spring Semester 2012
Outline • Hypothesis • About the Lodgepole Pine • Location • Importance • Reproduction • Cones • Methods • Results • Discussion • Citations
Hypothesis • Due to the strong westerly winds on Colorado’s Rocky Mountains, I hypothesize cone density on Lodgepole Pines will vary by hill slope direction, particularly on east-facing slopes in areas around MRS. • Relates to winter ecology because the LP has ~26 month pollen-cone and seen-cone bud Initiation… (Owens, 2006)
More on Lodgepole Pine • Location: • Pinus contorta extends from the Mackenzie district of the Yukon in Canada, to southern Colorado in the Rocky Mountains and northern Baja (Owens, 2006) • Lodge Pole pines are important because they account for about 7% of Rocky Mountain forests. • Distribution map: • Pinus contorta subsp. contorta • Pinus contorta subsp. latifolia • Pinus contorta subsp. murrayana
Lodgepole Importance • Ecological • Protective cover for watersheds • Wildlife Habitat •Aesthetic value for recreation • Economic Importance • Valuable source of timber products • One of the most extensively harvested trees in west.
Points on Lodgepole Reproduction • Reproduction • The cones are serotinous • “Serotinous cones do not open at maturity, but remain closed until the resin bond between cone scales is melted.” (Knapp and Anderson, 1980) • It is a fire adapted tree • Lodgepole pines have fairly thin bark, which reduces their defenses against fires. • Tend to outcompete each other for resources, often leaving many of them to dry up and die. • These dead Lodgepoles then become a fuel source for a future fire, increasing the heat needed for reproduction.
Cones • Opening the fire adapted cone • Temperatures ranging from 40-69º C have been reported as sufficient to open the cones. • (104º-156ºF) • Seeds inside the cones DO NOT lose viability with age! • “Although direct sunlight can, in some circumstances, open the cones, fire normally releases the seeds to the favorable seedbeds.” (Knapp and Anderson, 1980)
Methods • Location: Surrounding areas of MRS • 3.0m x 3.0m area • How much shade? • Count number of Lodgepole Pines • Direction hill slope faces • South • North • East • Flat • Approximate tree height • Count number of cones on each tree • Total number • Use binoculars
Results South-face slope? •What’s going on here? Avg. cones East: 16.14 North: 17.21 South: 49.08* Flat: 15.38 *contained outlier
Other Results • Seems to be no correlation between slope-face direction and cone density… • Relationship? •”Lodgepoles are quick to occupy a site… full of sunlight” (Owens, 2006) •Does contain outlier
Discussion • HYPOTHESIS FAILED? • Why? • Cones only need to get to a certain temperature to release seeds. • If ground is on fire, wind direction might not make a difference. • Remember: cones remain closed until the resin bond between cone scales is melted. (Knapp and Anderson, 1980) • Relationship between shade and cones? Maybe… • Future projects.
Citations • A.K. Knapp and J.E. Anderson. “Effect of Heat on Germination of Seeds from Serotinous Lodgepole Pine Cones.” American Midland Naturalist , Vol. 104, No. 2 (Oct., 1980), pp. 370-372 • Owens, J. "The Reproductive Biology of the Lodgepole Pine." Forest Genetics Council of British Columbia. (2006): 1-62. Print.